A selfdeveloped high⁃pressure CO2⁃crude mixing container is used to mix up CO2 and waxy crude oil respectively under reservoir condition, and gelling and yielding properties of the waxy crude oil are studied by gas chromatograph, DSC, rheological measurement, microscopic observation and other instruments. A brief summery about the effect of CO2 pretreatment on waxy crude oil was given. After treated by CO2, the reduction of light component in the waxy crude oil can inhibit the wax dissolution and increase the wax appearance temperature of waxy crude oil. The size of wax crystals becomes smaller and disperser after treated by CO2, which gives rise to the enhancement of the gel structure and the depravation of the low⁃temperature rheological property. With the increase of the pressure of CO2 during mixing process, the gelling and yielding properties of waxy crude oil are changed more and more obviously.